Biochem Rxns - DSA

Question 1

Recall the principles of free energy

Answer 1

• Delta G = 0 is equilibrium
• Delta G < 0 is spontaneous
• Delta G > 0 is non-spontaneous

Question 2

Recall the two Reaction Drivers

Answer 2

• Mass Action (Le Chatlier’s Principle)

- Input of energy (coupled rxns)

Question 3

Describe acid base balance and the role of the kidneys

Answer 3

• kidneys regulate blood pH by removing protons as NH4+.
• Kidneys reabsorb HCO3- to raise pH.
• low blood pH facilitates HCO3 reabsorption and H+ removal

Question 4

Metabolic Acidosis: pH, pCO2, HCO3, and Compensation

Answer 4

• pH is down, pCO2 is down, HCO3 is down, Hyperventilation

Question 5

Respiratory Acidosis: pH, pCO2, HCO3, and Compensation

Answer 5

• pH is down, pCO2 is up, HCO3 is up, increased renal HCO3 absorption

Question 6

Metabolic Alkalosis: pH, pCO2, HCO3, and compensation

Answer 6

• pH is up, pCO2 is up, HCO3 is up, Hypoventilation

Question 7

Respiratory Alkalosis: pH, pCO2, HCO3, and compensation

Answer 7

• pH is up, pCO2 is down, HCO3 is down, decreased reabsorption of HCO3

Question 8

2 factors affecting enzyme activity

Answer 8

• Temperature

- pH

Question 9

Describe the location and function of gastric proton pump inhibitors.

Answer 9

• Found in parietal cells that line gastric lumen.
• Pump H+ into lumen where it makes HCl
• proton pump inhibitors can be used to treat too much acid like omeprazole, and lansoprazole.

Question 10

What is Km in enzyme kinetics?

Answer 10

Km describes the enzyme substrate affinity. The lower the Km the higher the affinity. It is a numerical representation of the concentration of substrates when rxn is at 1/2 Vmax

Question 11

Describe competitive inhibition, and its affects on Vmax/Km

Answer 11

Inhibitor binds active site. Can be overcome with more substrate. No affect on Vmax. Increase in Km.

Question 12

Describe noncompetitive inhibition and its affect on Vmax/Km

Answer 12

Binds to E and ES at site other than active site. Decreased Vmax, unchanged Km.

Question 13

Describe uncompetitive inhibition and its affect on Vmax/Km

Answer 13

Only binds to the ES complex. Decreases Km and Vmax by the same factor.

Question 14

What OxPhos enzyme is affected by Cyanide?

Answer 14

• Cytochrome C

Question 15

What is an allosteric enzyme?

Answer 15

Enzyme that noncovalently binds to a site other than catalytic site. Affects substrate by inducing conformational changes.

Question 16

What is a proenzyme? Give two examples.

Answer 16

An inactive precursor to an enzyme. Pepsinogen—>pepsin. Trypsinogen—> trypsin.

Question 17

What key enzymes are found in serum after MI?

Answer 17

• KDH-1, CK-MB, AST.

Question 18

What is high serum troponin indicative of?

Answer 18

MI. Maximum sensitivity 10-24 hours following MI.